Pulsed lasers are used in a wide variety of applications ranging from signal sources in telecommunications systems to optical sources in sensing and measuring equipment. Q-switched lasers, for example, provide high power, short duration pulses for optical sensing functions, optical time domain reflectometry, and the measurement of nonlinearities in optical fibers. Illustratively, Q-switched lasers are capable of generating peak pulse powers of the order of a few hundred watts or more at repetition rates in the tens of kilohertz range. Pulse durations of about 1-100 nanoseconds are typical. Mode-locked lasers, on the other hand, may serve as high speed (e.g., multi-gigabit) signal sources in telecommunications systems, particularly soliton transmission systems. As such, the mode-locked laser may generate peak pulse powers of a few hundred milliwatts at repetition rates in excess of 10 Ghz. Pulse durations of a few picoseconds are typical.
Q-switched and mode-locked lasers have been extensively reported in the scientific literature. Two basic structures have been successfully demonstrated: a fiber laser ring topology of the type described by F. Fontana et al. in U.S. Pat. No. 5,381,426 issued on Jan. 10, 1995 and a Fabry-Perot (FP) fiber laser configuration of the type shown in U.S. Pat. No. 5,450,427 granted to M. E. Fermann et al. on Sep. 12, 1995. Most conventional laser designs rely on the use of an electro-optic, acoustic-optic or absorption modulators. These modulators are all bulk optic components, rendering the overall laser design less integrable, or limited to certain configurations or materials.
Thus, a need remains in the art for a relatively simple switched laser design.